drm/nva3: implement support for copy engine

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nv50_graph.c b/drivers/gpu/drm/nouveau/nv50_graph.c
index 5794cde..e25cbb4 100644
--- a/drivers/gpu/drm/nouveau/nv50_graph.c
+++ b/drivers/gpu/drm/nouveau/nv50_graph.c
@@ -939,7 +939,7 @@
 	return 1;
 }
 
-static int
+int
 nv50_graph_isr_chid(struct drm_device *dev, u64 inst)
 {
 	struct drm_nouveau_private *dev_priv = dev->dev_private;